Origin:
Possibly native to North America.
Biology:
Aphids in this genus are the most common aphid pests of conifers, including spruce, pine, and fir. There are around 175 different species in the genus Cinara, and they are specific to conifers and do not attack other kinds of trees. They feed primarily on soft twigs and branches, but may be found on the trunk of the tree or even the roots. Conifer aphids produce large quantities of honeydew, which in turn attracts ants, yellow jackets, or other sugar-feeding insects to the infested tree. The honeydew may also encourage the growth of sooty mold, which covers needles with a dark, powdery layer. There can be several generations each year, with large populations existing by the end of the summer.
Identification:
Conifer aphids are fairly large in the adult stage, and are dark gray with light gray lateral stripes on the abdomen in this stage. The nymph stage tends toward lighter gray with darker spots that enlarge with each successive stage. They produce very little wax around them while on trunks or branches, but the early nymph stages do produce larger amounts of white wax while feeding on the needles.
Characteristicts Important to Control:
An application of a labeled insecticide to the foliage, stems, and trunks should effectively kill these aphids. Winter applications of dormant oil will help to reduce overwintering stages in the trunk and larger branches. Since they produce very little wax there is no need to add a wetting agent to the spray solution. The aphids are usually present on conifers from late spring to the end of the summer.
